John fitzgerald



(No Model.)

I J. FITZGERALD.

FELD DEVIGL FOR GRINDING MILLS. No. 248,300.

Patented Oct. 18,1881.

| lllll" UNITED STATES PATENT OEEICE.

JOHN FITZGERALD, OF BROOKLYN, NEV YORK.

FEED DEViCE FOR GRlNDlNG-NIILLS.

SPECIFICATION forming part of Letters Patent No. 248,300, dated October 18, 1881.

Application filed February 24, 1881.

To all whom t may concern:

Be it known that I, JOHN FITZGERALD, of the city of Brooklyn, in the count-y of Kings and State of New York, am the inventor of Improvements in Grinding-Mills, of which the following is a full, clear, and exact description,reference being had to the accompanying drawings, forming part of this specification.

My invention relates to a grinding-mill such as is employed in grinding the materials for paints, 85e., and more particularly to the devices for feeding the materials to be ground to the principal grinding-stones; and my invention consists in the combination, with the principal grinding-stones ofa mill, having a conical plate fixed tothe lower or moving stone, about the axis, on the upper side thereof, of a cylindrical hopper capable of vertical adjustment in the eye of the casing of the upper or stationary stone, and having cast upon it or otherwise rigidly secured to it on its interior, at its base-line, the feeding ring valve hereinafter described, together with the radial arms and adjusting-screws hereinafter specified, as and for the purpose set forth.

Figure l is a vertical central sectional view ofthe principal grinding-stones of a mill, showing my improved feeding devices in position upon them. Fig. 2 is a top plan of my iinproved hopper and feeding ring valves, and Fig. 3 is a bottom plan of the same.

A is the lower or moving stone. Upon the upper face of this stone, and about its hub or axis, is fixed the conical plate a, as shown.

Bis the upper or stationary stone; b, the eye of the casing b', the interior face of which is turned off smooth to fit the exterior of the cylindrical hopper O, the outer surface of which is also turned off. e

The hopper is arranged to fitneatly to the ianged eye b of the casing b', and it has the feathers c, which fit into suitable grooves in the said flanged eye, to hold the hopper stationary with the grinder B.

The base-line of the hopper extends down-V ward to the plane of the baseline of the conical plate a, and it has cast upon its interior face at said hase-line the ring D.

The under face of the ring D is tted to the upper face of the conical plate a, and has cut or formed in it the radial feedgrooves d, as

(No model.)

seen plainly in Fig. 3. The upper face of the ring slopes upward to the line of the interior of the hopper.

Upon the upper part of the hopper G, preferably at the mouth thereof, are cast or otherwise rigidly xed the radial arms or lugs c. A threaded opening is cut in each of these arms or lugs, with which opening engages the upper end of a vertical adjusting-screw,E, the lower ends of said screws working in vsteps e on the upper face of the casing b ofthe stone B, as shown.

Stirring or mixing devices, as shown at F, Fig. l, may be arranged to revolve within the hopper, as shown, to cause the thorough mixing1 and agitation of the contained material.

It is well known that, in order to secure the best results in grinding, the material to be ground should be fed to the stones with precision and in a certain and unvarying quantity. It is also well known that it frequentlybecomes necessary to alter and regulate the feed of the material to the grindingstones in order to accomplish satisfactory results.

It is evident that when my described hopper is charged with material to be ground, and the hopper is lowered until the ring D rests upon the conical plate c, and the mill is set in motion, it' the feed is not fast enough through the grooves d, the ring D may be raised more or less above and away from said plate by turning the adjusting-screws E, the-hopper carrying the ring being thus moved vertically inthe eye of the casing ofthe upper stone; and it is evident that an exceedingly nice and close adjustment of the ring D and the plate atconstituting the feed devices) to each other may be thus accomplished.

The weight of the hopper and its contained material will generally be found sufficient to cause the ring D to bear properly upon the plate c; but if the emergency occurs, the hopi per may be weighted at the lugs, as shown.

What I claim as my invention, and desire to secure by Letters Patent, is-

In a grinding-mill, the combination, with thelower or movingstone, A,havingtheconical plate a fixed about its hub, and the upper or stationary stone, B, having the casingb, with the flan ged and grooved eye b, of the cylindrical hopper C, provided with the feathers c, and fitted to and capable of vertical movement in the Witness my hand this 23d day of February, eye of said casing b', and'having cast or other- A. D. 1881.

wise rigidly fixed to its interior, at its base line, the feed ring valve D, together with the JOHN FI EZGERALD arms orlugs o andthe vertical adj Listing-screws i \Vitnesses:

E, all constructed and arranged to operate as A. G. N. VERMILYA,

and for the purpose specified. i HENRY EIGI-ILING. 

